* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font: 20px/1.5 sans-serif;
    color: #333333;
  }
  
  a {
    color: #333;
    text-decoration: none;
  }
  
  #div1 {
    width: 200px;
    margin: 0 auto;
    line-height: 25px;
  }
  
  ul {
    list-style: none;
  }
  
  dl {
    background: #eee;
    display: none;
  }
  
  .active {
    background: #F90;
  }
  
  .container-right {
    height: 100%;
    width: 795px;
  
    background-color: rgba(255, 255, 255, 0.8);
    border-radius: 10px;
     padding: 20px;
  
     overflow: auto;
  
  }
  
  .wrapper {
    margin: 0 auto;
    width: 1200px;
  }
  
  body {
    background-color: #ffffff;
  }
  
  /* 头部区域 */
  .header {
    height: 100px;
    background-color: rgb(236, 228, 228);
  }
  
  .header .wrapper {
    padding-top: 29px;
    display: flex;
  }
  
  /* logo */
  .logo a {
    display: block;
    width: 310px;
    height: 60px;
    background-image: url(../images/logo.png);
    font-size: 0;
  }
  
  /* 导航 */
  .nav {
    margin-left: 102px;
  }
  
  .nav ul {
    display: flex;
  }
  
  .nav li {
    margin-right: 24px;
  }
  
  .nav li a {
    display: block;
    padding: 6px 8px;
    line-height: 27px;
    font-size: 19px;
  }
  
  /* actvie 类选择器，表示默认选中的a */
  .nav li .active,
  .nav li a:hover {
    border-bottom: 2px solid #00a4ff;
  }
  
  /* 搜索 */
  .search {
    display: flex;
    margin-left: 64px;
    padding-left: 19px;
    padding-right: 12px;
    width: 412px;
    height: 40px;
    background-color: #f3f5f7;
    border-radius: 20px;
  }
  
  .search input {
    flex: 1;
    border: 0;
    background-color: transparent;
    /* 去掉表单控件的焦点框 */
    outline: none;
  }
  
  /* ::placeholder 选中就是 placeholder 属性文字样式*/
  .search input::placeholder {
    font-size: 14px;
    color: #999;
  }
  
  /* 父级是flex布局，子级变弹性盒子：加宽高生效 */
  .search a {
    align-self: center;
    width: 16px;
    height: 16px;
    background-image: url(../images/search.png);
  }
  
  /* 用户 */
  .user {
    margin-left: 30px;
    margin-top: 4px;
  }
  
  .user img {
    margin-right: 5px;
    /* vertical-align 行内块和行内垂直方向对齐方式 */
    vertical-align: middle;
  }
  
  .user span {
    font-size: 16px;
    color: #666;
  }